function r=chapter1run()
    n2=GetMesh(@g2,@f2)
    'The required minimun mesh is ', n2
    u2=FivePointPoisson1(@f2,@g2,n2);
    err =0;
    for i = 1:n2+1
        for j = 1:n2+1
            err_t(i,j) = abs(g2((i-1)/n2,(j-1)/n2)-u2(i,j));
            if err_t(i,j)>err
                err = err_t(i,j);
            end
        end
    end
    err
    %mesh(err_t);
    mesh(u2);
    
    'press any key to continue'
    pause on;
    pause;   
    
    n1=GetMesh(@g1,@f1);
    'The required minimun mesh is ', n1
    u1=FivePointPoisson1(@f1,@g1,n1);
    err = 0;
    for i = 1:n1+1
        for j = 1:n1+1
            err_t(i,j) = abs(g1((i-1)/n1,(j-1)/n1)-u1(i,j));
            if err_t(i,j)>err
                err = err_t(i,j);
            end
        end
    end
    err
    %mesh(err_t);
    mesh(u1);
    
end